Does sensory relearning improve tactile function after carpal tunnel decompression? A pragmatic, assessor-blinded, randomized clinical trial

Despite surgery for carpal tunnel syndrome (CTS) being effective in 80-90% of cases, chronic numbness and hand disability can occur. The aim of this study was to investigate whether sensory relearning improves tactile discrimination and hand function after decompression. In a multi-centre, pragmatic, randomized, controlled trial, 104 patients were randomized to sensory relearning (n=52) or control (n=52) group. 93 patients completed 12 week follow-up. Primary outcome was the Shape-Texture Identification (STI) test at 6 weeks. Secondary outcomes were touch threshold, touch localisation, dexterity and self-reported hand function. No significant group differences were seen for the primary outcome (STI) at 6 weeks or 12 weeks. Similarly, no significant group differences were observed on secondary outcomes, with the exception of self-reported hand function. A secondary Complier-Averaged-CausalEffects (CACE) analysis showed no statistically significant treatment effect on the primary outcome. Sensory relearning for tactile sensory and functional deficits after carpal tunnel decompression is not effective

Cortical disinhibition occurs in chronic neuropathic, but not in chronic nociceptive pain

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to examine the relationship between chronic neuropathic pain after incomplete peripheral nerve lesion, chronic nociceptive pain due to osteoarthritis, and the excitability of the motor cortex assessed by transcranial magnetic stimulation (TMS). Hence in 26 patients with neuropathic pain resulting from an isolated incomplete lesion of the median or ulnar nerve (neuralgia), 20 patients with painful osteoarthritis of the hand, and 14 healthy control subjects, the excitability of the motor cortex was tested using paired-pulse TMS to assess intracortical inhibition and facilitation. These excitability parameters were compared between groups, and the relationship between excitability parameters and clinical parameters was examined.</p> <p>Results</p> <p>We found a significant reduction of intracortical inhibition in the hemisphere contralateral to the lesioned nerve in the neuralgia patients. Intracortical inhibition in the ipsilateral hemisphere of neuralgia patients and in both hemispheres of osteoarthritis patients did not significantly differ from the control group. Disinhibition was significantly more pronounced in neuralgia patients with moderate/severe pain intensity than in patients with mild pain intensity, whereas the relative compound motor action potential as a parameter of nerve injury severity did not correlate with the amount of disinhibition.</p> <p>Conclusions</p> <p>Our results suggest a close relationship between motor cortex inhibition and chronic neuropathic pain in the neuralgia patients, which is independent from nerve injury severity. The lack of cortical disinhibition in patients with painful osteoarthritis points at differences in the pathophysiological processes of different chronic pain conditions with respect to the involvement of different brain circuitry.</p

Effects of Carpal Tunnel Syndrome on Dexterous Manipulation Are Grip Type-Dependent

abstract: Carpal tunnel syndrome (CTS) impairs sensation of a subset of digits. Although the effects of CTS on manipulation performed with CTS-affected digits have been studied using precision grip tasks, the extent to which CTS affects multi-digit force coordination has only recently been studied. Whole-hand manipulation studies have shown that CTS patients retain the ability to modulate multi-digit forces to object mass, mass distribution, and texture. However, CTS results in sensorimotor deficits relative to healthy controls, including significantly larger grip force and lower ability to balance the torques generated by the digits. Here we investigated the effects of CTS on multi-digit force modulation to object weight when manipulating an object with a variable number of fingers. We hypothesized that CTS patients would be able to modulate digit forces to object weight. However, as different grip types involve the exclusive use of CTS-affected digits (‘uniform’ grips) or a combination of CTS-affected and non-affected digits (‘mixed’ grips), we addressed the question of whether ‘mixed’ grips would reduce or worsen CTS-induced force coordination deficits. The former scenario would be due to adding digits with intact tactile feedback, whereas the latter scenario might occur due to a potentially greater challenge for the central nervous system of integrating ‘noisy’ and intact tactile feedback. CTS patients learned multi-digit force modulation to object weight regardless of grip type. Although controls exerted the same total grip force across all grip types, patients exerted significantly larger grip force than controls but only for manipulations with four and five digits. Importantly, this effect was due to CTS patients’ inability to change the finger force distribution when adding the ring and little fingers. These findings suggest that CTS primarily challenges sensorimotor integration processes for dexterous manipulation underlying the coordination of CTS-affected and non-affected digits.The article is published at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.005375

Effects of Carpal Tunnel Syndrome on Dexterous Manipulation Are Grip Type-Dependent

Carpal tunnel syndrome (CTS) impairs sensation of a subset of digits. Although the effects of CTS on manipulation performed with CTS-affected digits have been studied using precision grip tasks, the extent to which CTS affects multi-digit force coordination has only recently been studied. Whole-hand manipulation studies have shown that CTS patients retain the ability to modulate multi-digit forces to object mass, mass distribution, and texture. However, CTS results in sensorimotor deficits relative to healthy controls, including significantly larger grip force and lower ability to balance the torques generated by the digits. Here we investigated the effects of CTS on multi-digit force modulation to object weight when manipulating an object with a variable number of fingers. We hypothesized that CTS patients would be able to modulate digit forces to object weight. However, as different grip types involve the exclusive use of CTS-affected digits (‘uniform’ grips) or a combination of CTS-affected and non-affected digits (‘mixed’ grips), we addressed the question of whether ‘mixed’ grips would reduce or worsen CTS-induced force coordination deficits. The former scenario would be due to adding digits with intact tactile feedback, whereas the latter scenario might occur due to a potentially greater challenge for the central nervous system of integrating ‘noisy’ and intact tactile feedback. CTS patients learned multi-digit force modulation to object weight regardless of grip type. Although controls exerted the same total grip force across all grip types, patients exerted significantly larger grip force than controls but only for manipulations with four and five digits. Importantly, this effect was due to CTS patients’ inability to change the finger force distribution when adding the ring and little fingers. These findings suggest that CTS primarily challenges sensorimotor integration processes for dexterous manipulation underlying the coordination of CTS-affected and non-affected digits

Expectancy and Treatment Interactions: A Dissociation between Acupuncture Analgesia and Expectancy Evoked Placebo Analgesia

Recent advances in placebo research have demonstrated the mind's power to alter physiology. In this study, we combined an expectancy manipulation model with both verum and sham acupuncture treatments to address: 1) how and to what extent treatment and expectancy effects — including both subjective pain intensity levels (pain sensory ratings) and objective physiological activations (fMRI) — interact; and 2) if the underlying mechanism of expectancy remains the same whether placebo treatment is given alone or in conjunction with active treatment. The results indicate that although verum acupuncture + high expectation and sham acupuncture + high expectation induced subjective reports of analgesia of equal magnitude, fMRI analysis showed that verum acupuncture produced greater fMRI signal decrease in pain related brain regions during application of calibrated heat pain stimuli on the right arm. We believe our study provides brain imaging evidence for the existence of different mechanisms underlying acupuncture analgesia and expectancy evoked placebo analgesia. Our results also suggest that the brain network involved in expectancy may vary under different treatment situations (verum and sham acupuncture treatment).National Center for Complementary and Alternative Medicine (U.S.) (PO1-AT002048)National Center for Complementary and Alternative Medicine (U.S.) (R21AT00949

Altered bodily perceptions in chronic neuropathic pain conditions and implications for treatment using immersive virtual reality

Chronic neuropathic pain is highly disabling and difficult to treat and manage. Patients with such conditions often report altered bodily perceptions that are thought to be associated with maladaptive structural and functional alterations in the somatosensory cortex. Manipulating these altered perceptions using body illusions in virtual reality is being investigated and may have positive clinical implications for the treatment of these conditions. Here, we have conducted a narrative review of the evidence for the types of bodily distortions associated with a variety of peripheral and central neuropathic pain conditions. In addition, we summarize the experimental and clinical studies that have explored embodiment and body transformation illusions in immersive virtual reality for neuropathic pain relief, which are thought to target these maladaptive changes, as well as suggesting directions for future research

Akute Zytokin-vermittelte thermische Hyperalgesie im Rattenmodell: Rolle von TRPV1

Diese Studie untersucht mittels Verhaltenstestungen (Plantartest, Frey-Haare) am Rattenmodell, ob die akute intrathekale Injektion des proinflammatorischen Zytokins Tumornekrosefaktor (TNF) eine taktile Allodynie und/oder eine thermale Hyperalgesie auslöst und ob das zytokin-induzierte schmerzassoziierte Verhalten durch die intrathekale Applikation des TRPV1 (transient-receptor-potential-vanilloid 1)-Agonisten Resinferatoxin (RTX) moduliert werden kann. Es wurde nachgewiesen, dass die intrathekale TNF-Injektion nach 24 h in den Dosierungen 2 ng und 200 ng im Vergleich zu den Vortesten eine signifikante taktile Allodynie und in den TNF-Dosierungen 20 ng und 200 ng eine signifikant unterschiedliche thermale Hyperalgesie auslöst. Durch anschließende intrathekale RTX- Applikation kann im Vergleich zu alleiniger intrathekaler TNF- Injektion ein signifikanter Anstieg der thermalen Rückzugslatenzen nach 24 Stunden in den TNF-Dosierungen 20 ng und 200 ng festgestellt und somit die Entstehung einer zuvor von TNF-induzierten thermalen Hyperalgesie verhindert und im Vergleich zur Kontrollgruppe auch eine Veränderung der thermalen Sensibilität festgestellt werden. Die Entwicklung einer taktilen Allodynie wird von der intrathekalen RTX-Injektion nicht beeinflusst. Aus den Ergebnissen kann ein von der TNF-Dosierung abhängiger analgetischer Wirkungseffekt von RTX vermutet und somit gefolgert werden, dass die Pharmakotherapie mit selektiven TRPV1-Agonisten wie RTX in der medikamentösen Behandlung neuropathischer Schmerzen einen entscheidenden Vorteil bietet. Als mögliches zelluläres Korrelat kommt eine durch TNF induzierte erhöhte TRPV1-Rezeptorexpression oder eine durch TNF induzierte verstärkte Hemmung spannungsabhängiger Calciumkanäle in Betracht. Diese Studie trägt zur weiteren Erforschung TRPV1-selektiver Pharmaka in der medikamentösen Therapie bei neuropathischen Schmerzsyndromen bei und bietet mittelfristig eine Grundlage für weitere klinische Studien

Interosepsjon som et relevant osteopatisk konsept: veien mot det interoseptive paradigmet

BAKGRUNN: D’Alessandro, Cerritelli og Cortelli foreslo i 2016 et skifte til ”det interoseptive paradigmet”. Dette skyldes at de nåværende osteopatiske forklaringsmodeller og forskningsfokuset er sentrert rundt proprioseptive og eksteroseptive nevrovitenskapelige konsepter. Dette nye paradigmet skal ifølge forfatterne være i bedre stand til å vekte de fysiologiske egenskapene til nervesystemet mot en klinisk kontekst. Det sentrale begrepet i paradigmet er interosepsjon. Oppgavens hensikt er å utbygge et teoretisk og praktisk fundament for hvordan begrepet interosepsjon har relevans for osteopati som fagfelt. Oppgavens problemstilling er: ”Hvilken relevans har konseptet interosepsjon for pasientbehandling i den manuelle osteopatiske profesjon?” METODE: Dette er ett narrativt litteraturstudie. For å skape en oversikt over tilgjengelig litteratur som knytter interosepsjon og osteopati sammen ble det gjennomført elektroniske litteratursøk i tre ulike databaser: MedLine/PubMed, PsycInfo og EmBase. RESULTAT: Tre artikler møtte alle inklusjonskriteriene. Disse artiklene inkluderer et narrativ litteraturstudie (artikkel 1), et kasus- kontrollstudie (artikkel 2) og en pilotstudie (artikkel 3). DISKUSJON: Først blir artikkel to og tre diskutert. Deretter presenteres en idé om tverrfaglig håndtering av pasienter med interoseptive forstyrrelser - av oss kalt ”den interoseptive pasient”. Videre diskuteres artikkel 1. På bakgrunn av dette blir det presentert en modell for hvordan osteopater kan imøtekomme interoseptive pasienter. KONKLUSJON: Konseptet interosepsjon har klinisk relevans for den osteopatiske profesjonen, både sett fra et tverrfaglig perspektiv og for hvordan osteopater leser, behandler og interagerer med interoseptive pasienter. Det er behov for mer forskning som knytter manuell behandling og osteopati sammen med interosepsjon